Which change in conditions would increase the volume of a fixed mass of gas?

https://www.ibchemistryninja.com/copy-of-ch-1-q-1-10-1

1 Answer

Increase temperature #T# or decrease pressure #P#.

Explanation:

We can use the Ideal Gas Equation to solve this question:

#PV = nRT#

Hre

  • #P# is pressure in #"Pa"#
  • #V# is volume in #"m"^3#
  • #n# is number of moles of gas
  • #R# is the universal gas constant, #"8.31 J/K mol"#
  • #T# is temperature in Kelvin

In your scenario, when mass is fixed, the number of moles will be fixed, too. So we can combine both constant terms #n# and #R# to give us:

#PV = kT#

where #k# is a constant.

Now, since we want to work out how volume changes, let's put #V# on the left-hand side and move #P# to the right-hand side:

#V = (k T) / P#

So from the equation, we can deduce that in order to increase volume, we can either increase temperature #T# or decrease pressure #P#.

Hope this helps!